Carlsbad Caverns National Park

Flora & Fauna

The diversity of habitats in the park, including permanent flowing water at Rattlesnake Springs, provides for an exciting array of wildlife. This diversity is further benefited by the position of the park at the intersection of the southern Rocky Mountain, northern Chihuahuan Desert, and southwestern Great Plains biogeographic provinces.

Many animals occur here at the geographic limits of their ranges. For example, several species of reptiles are at the edges of their distributions.

The deserts of the Southwest contain some of the highest diversity of mammals, birds, reptiles, and insects in the United States. The park provides important year-round habitat for top predators such as cougars, and nesting habitat for migratory species such as the large colonies of cave swallows and Brazilian (Mexican) free-tailed bats that raise their young in Carlsbad Cavern.

Rattlesnake Springs, a rare desert wooded riparian area that has been designated an Important Bird Area (IBA) by the National Audubon Society, draws birders from around the world to see some of the 300-plus species that have been noted there. The Carlsbad Cavern Natural Entrance is also an Audubon IBA because of the large colony of cave swallows that resides and breeds there in the summer.

For more information on the National Audubon Society's IBA program, see their website at www.audubon.org/bird/iba/index.htm (http://www.audubon.org/bird/iba/index.html)

Amphibians

Among the park's nine amphibians are two species of spadefoot toads, Couch's spadefoot and New Mexico spadefoot. The spadefoot toads are not true toads, but belong to the primitive family Pelobatidae. Spadefoots resemble true toads (family Bufonidae) in body form, but have smoother, thinner skin. The spadefoots are named for their large, sharp metatarsal tubercles that are used to dig backwards to depths of several feet.

Spadefoots are truly adapted to life in a desert, taking advantage of the short-lived ponds created by summer thunderstorms in order to breed. It is believed that sound or vibration, such as might be caused by rainfall, cues the spadefoots to emerge from underground and congregate at the ponds. Males engage in loud choruses to attract females and rush the breeding process before the ponds disappear. Spadefoots breed quickly in order to take advantage of favorable breeding conditions and to allow the eggs and larvae as much time as possible to develop.

The park's list also includes four species of true toads (family Bufonidae); as well as a cricket frog (believed to have been extirpated from the park in recent years) and two species of true frogs, the Rio Grande leopard frog and the non-native American bullfrog.

Birds

The list of birds that have been observed in the park includes a whopping 357 species. This huge list includes species that are year-round residents and nest here, neotropical migrants that nest in the park or pass through on the way to northern breeding grounds, winter residents, and occasional or rare species that wander in and may stay a while.

The park's common year-round residents include some interesting and colorful species. The ladder-backed woodpecker, the second-smallest North American woodpecker, is equally at home on a cactus stem or a sotol stalk as on a tree trunk—a useful adaptation when you live in desert shrublands with few trees. In fact, it was historically called cactus woodpecker.

The cactus wren is another year-round resident that is obviously at home with cacti, building nests in them for breeding as well as for roosting. This is the largest of the nine North American wren species, all of which have been seen in the park and six of which breed here. Rock wrens, black-throated sparrows, and northern mockingbirds are among the commonly seen year-round residents of the park.

Migratory species are numerous. The park provides some of New Mexico's prime breeding habitat for three state-threatened birds: Bell's vireo, gray vireo, and varied bunting. Bell's vireos nest at Rattlesnake Springs, the park's wooded riparian area, while gray vireos nest in dry canyons with small desert trees such as oaks and junipers. Varied buntings nest in dry canyons with somewhat larger trees.

Cave Swallows

Another migratory bird that nests in the park is the cave swallow. The cave swallow, a close relative of the cliff swallow, can be seen from early February to late October (sometimes even November) nesting just inside the entrance to Carlsbad Cavern, in the so-called twilight zone. The swallows provide entertainment for visitors by chattering, swooping, and making spectacular dives into and around the mouth of the cave.

The first cave swallows appeared in what is now Carlsbad Caverns National Park prior to 1930 and spread to Carlsbad Cavern in 1966. They make open cup-shaped nests out of mud that are used for several years with the birds frequently adding to the nest annually. Unlike the cliff swallow, a cave swallow's nest is not fully enclosed. It is shaped like a small half-cup; it is constructed of mud and plant fibers, and lined with feathers.

Cave swallows are insectivorous. They feed on a wide variety of insects and are considered to be opportunistic feeders. All prey is taken in flight with the birds only going to the ground to collect mud for nests.

A local researcher, Steve West, has been banding cave swallows at Carlsbad Cavern since 1980. In 2005, he recaptured a bird that had been banded in 1993 as a hatch-year individual, making it 12 years old! While most of the banding has been done to study the life history of the species, the original reason was to discover the winter range of the bird. One bird banded at Carlsbad Cavern was found dead in Jalisco, on the Pacific coast of Mexico, and provided the first clue of their winter range south of the United States.

The banding project continues and is one of the longest on-going banding studies in the United States. To date 5,000 volunteers from 38 states and 17 countries have helped to gather this information

Crustaceans

Most of the known crustaceans in Carlsbad Caverns National Park are cave-dwelling creatures. These include intriguing animals such as copepods called Cyclops vernalis and branchiopods called water fleas (Holopedium amazonicum).

Also among the crustaceans are the group called isopods, including groups such as sowbugs, pillbugs and woodlice. The park has several species both below and above ground. Unfortunately, the above-ground pillbugs are probably not native.

Crayfish are the best-known crustaceans and have been found at Rattlesnake Springs. Identified as the red swamp or Louisiana crayfish, they also are not native to New Mexico.Fish

Five species of fish have been found at Rattlesnake Springs. Two of these species are native—roundnose minnow and greenthroat darter. The other three species are non-native fish and they include green sunfish, largemouth bass, and western mosquitofish. In the summer of 2007, a project was completed to remove the non-native green sunfish and largemouth bass from the pond. These fish were relocated to an appropriate location on the Pecos River, where they are native. The western mosquitofish have only been found in the natural channel and these fish are removed when found.

Insects, Spiders, Centipedes, and Millipedes

The park has a rich fauna of invertebrate animals, most of which have not been formally surveyed. Nearly every time someone undertakes a study of the park's insects or other invertebrates, exciting revelations are made. For example, in 2003, Dr. John Abbott took his University of Texas class on a field trip to Rattlesnake Springs and documented a new species of damselfly for New Mexico, called Lenora's dancer. In 2005, the park sent some fireflies, also called "lightning bugs," to an expert for identification. It turned out that these insects, which are actually beetles, were a new genus for the state: Photuris.

In 2006, a long-term survey of the park's moths was undertaken by lepidopterist Eric Metzler. Results are very preliminary, but hundreds of species have already been collected, including some that may be entirely new species. Surveys of the park's butterflies have yielded more than 100 species, including the Carlsbad agave skipper and the Sandia hairstreak, the state butterfly of New Mexico. Thanks largely to the wooded riparian habitat with permanent water at Rattlesnake Springs, the park's list of damselflies and dragonflies is well over 60 species and includes such picturesque names as the saffron-winged meadowhawk (a dragonfly) and the desert firetail (a damselfly).

The park's underground environs also harbor intriguing invertebrate. There are three species of cave (or camel) crickets known from Carlsbad Caverns National Park. These cricket-like insects have rounded backs and are nocturnal. Many cave crickets live in the front parts of caves only to leave at night to forage. Their diet consists of small insects, microbes, possibly algae or fungi, and each other. A number of other creatures, in turn, feed on cave crickets. These include bats, raccoons, and ringtails. Cave crickets and their eggs, and droppings are important food sources for other cave organisms.

The three known species from the park are Ceuthophilus carlsbadensis, C. longipes and C. conicaudus. As with many insects, these animals have not been given common names.

Ceuthophilus carlsbadensis is found in many caves throughout New Mexico and Texas and is very common in Carlsbad Cavern. It actually shows very little adaptation for living in caves and tends to live in food-rich areas, such as cave rooms with bat guano. On the other hand, Ceuthophilus longipes (known from numerous park caves) is more cave-adapted and is found in food-poor areas. C. longipes is smaller and lighter in color and has longer legs and antennae than C. carlsbadensis. The third species, Ceuthophilus conicaudus, falls between the other two species in cave adaptation traits. It is only found sparsely in Carlsbad Cavern, but is the dominant cave cricket in a few other park caves.

Other invertebrates found in the caves include isopods, troglophilic beetles, millipedes, centipedes, various spiders, and primitive creatures related to bristletails and silverfish.

Mammals

The park's 67 mammal species include some that are rarely seen, such as the black bear and spotted skunk. Some of them are non-natives, including the eastern fox squirrel and Barbary sheep. Others are native animals that have been restored through reintroduction programs in the area, including javelina and pronghorn. Merriam's elk became extinct around the turn of the last century and the closely related Rocky Mountain elk was brought into the area to replace it. Desert bighorn sheep were extirpated from the park in the 1960s. Up to six other species may have been extirpated since European settlement.

Other native mammals in the park range from mule deer and cougar (mountain lion) to the small mammals such as ringtails; several species of ground squirrels, deer mice, and kangaroo rats; the desert shrew; and the Chihuahuan Desert pocket mouse, which was not documented in the park until the 21st Century.

Of course, the most famous of the park's mammals are the bats, especially the large colony of Brazilian (or Mexican) free-tail bats that wows visitors every evening from spring through fall with its spectacular outflight. In all, the park hosts 17 different species of bats that use a variety of different habitats.

Bats

The most famous of the park's mammals are the bats. The park hosts 17 different bat species. The large colony of Brazilian (or Mexican) free-tail bats wows visitors every evening from spring through fall with its spectacular outflights. Two other species have also been found regularly in Carlsbad Cavern—cave myotis and fringed myotis bats. They typically roost in a different part of the cave and their exit flight is typically later in the evening than that of the free-tail bats.

But not all bat species roost in caves. Among the other species using the park are Eastern red bats and hoary bats, which roost in trees, and Western pipistrelle bats, which roost on rock cliffs and in cracks.

Bats are mammals, which means that they give live birth to their young (not lay eggs), are warm-blooded, have fur (not feathers), and are fed breast milk (not insects) by their mothers. Bats are the only true flying mammals. All the bats in the area around Carlsbad Caverns National Park are insectivores, which means they eat insects.

The Brazilian free-tail bats weigh about 13 grams, which is equivalent to the weight of three nickel coins. Their wingspan is approximately 11 inches. Bat numbers in the Cavern are variable. The resident colony was around 400,000 in summer of 2005. During the spring and fall migration, the bat numbers in the cavern were documented as high as 793,000 in 2005. There are seasonal fluctuations of the numbers, as well as daily fluctuations. Researchers from Boston University have been assisting the park in getting accurate population estimates. They use advanced thermal infrared imaging cameras coupled with a custom-written visual recognition software program to count the bats.

At Carlsbad Cavern, the resident colony should not be called the maternity colony because it is typically greater than 50 percent male. The males and females roost mixed together in the same site. In many sites outside of the park, the really large Brazilian free-tail bat colonies are almost exclusively female and the males roost in smaller groups.

For lots more fascinating information on bats, check out the Bat Conservation International website at http://www.batcon.org (http://www.batcon.org/home/default.asp).

Feeding in Brazilian Free-Tail Bats:

Brazilian (Mexican) free-tail bats eat insects, typically moths and beetles. Studies examining insect remains in free-tailed bat guano rarely, if ever, encounter evidence of mosquito consumption. Some other bat species do eat mosquitoes, however. A pregnant or lactating bat can eat from 50 to 100 percent of her body weight in insects each night. It is estimated that 100,000 bats can eat more than 1,000 pounds of insects each night.

They can catch prey directly in their mouth and by using their tail membrane or wings to assist in capturing the flying insects. Like many bats, they use echolocation to detect and catch the insects. The free-tailed bats have been observed feeding 36 miles from the Cavern. They have been found in every direction from the park. Typically they head to a water source after emergence.

Not far away in Texas, Brazilian free-tail bats have been documented feeding on insects at 10,000 feet. At this altitude, they are following and eating cotton bollworm moths (corn earworm moth), army cutworm moths, tobacco budworm moth, and other costly agricultural pests. They can fly at speeds of up to 60 mph. When the bats are emerging from the cavern, they can be traveling at around 35 mph. Unlike many other bat species, they typically do not use night roosts. Except for the moms that come back to feed their pups during the night, they fly all night.

Brazilian Free-Tail Bat Outflight:

What triggers emergence of the bats from the cave at night is something of a mystery. The only scientific correlation found with the emergence of bats is civil twilight (28 minutes past sunset). Bats flying around the roost site can see light entering Bat Cave from Carlsbad Cavern's second natural entrance. But based on the variability of the bats emergence, civil twilight is not the only explanation.

The outflight can last up to three hours, depending on a variety of factors, including the number of bats in the colony. Bats can begin returning at any time, particularly when they have pups to nurse. The number of bats returning usually peaks around dawn. When the bats fly over the amphitheater, you can hear their wings and also smell them. The Brazilian (Mexican) free-tail bats have a unique odor—not all bat species have an obvious odor. The bats spiral out of the cave in a counter-clockwise direction. It is not known why they choose to spiral counter-clockwise, but current research suggests a variety of factors play roles. One of these may be an internal 'compass' in the bats that is based on the earth's magnetic poles.

Mollusks

Mollusks can be found in nearly every ecosystem on earth, so it's not surprising to find them in Carlsbad Caverns National Park. In much of the American Southwest, isolation of suitable habitats often results in unique, localized species. Mountain ranges with increased moisture and isolated by vast stretches of desert have turned up different species. In isolated springs, the same process can be demonstrated as the original range of a species shrinks as an area becomes more arid. This can continue until a formerly widespread species is now limited to small springs, often isolated from the nearest population by many miles. For example, the snail called ovate vertigo is a very common fossil throughout much of the Southwest, but today exists at only a few locations. It is known only in this park from unoccupied shells found at Rattlesnake Springs. The nearest population is several miles away at another spring.

The body of a mollusk is generally composed of the shell and the fleshy, living part. The fleshy parts of a mollusk can be further divided into the foot and the visceral mass. The foot is a distinctive feature of the mollusk, adapted in a variety of ways for locomotion. The visceral mass includes the organs for digestion, circulation, reproduction, and respiration.

In a brief survey of mollusks in the 1980s, many species were found in the park. Most are snails, both aquatic and terrestrial. One of the rarest is called the Guadalupe woodland snail, which was named Ashmunella carlsbadensis after being originally discovered nearby. The Guadalupe woodland snail is reportedly more tolerant of dry conditions and lower elevations than others in the Guadalupe Mountains. The park also has some species know as fingerclams, which are bivalves—related to clams, oysters and scallops. Instead of having spiral-like shells like snails, their shells consist of two symmetrical valves.Other Invertebrates (Corals, Sponges, Worms, Etc.)

Horsehair worms are the aquatic adult phase of little-known invertebrate animals. The immature stages are parasites in the bodies of grasshoppers, crickets, cockroaches, and some beetles. When mature, they leave the host to lay eggs. These interesting creatures are not parasites of humans, livestock, or pets, and pose no public health threat. The adult "worms" mate in water and females lay long, gelatinous strings of eggs. After the eggs hatch, scientists believe that each larva forms a protective covering or cyst. If a suitable insect eats the cyst, then the protective covering dissolves and the released larva bores through the gut wall and into the body cavity of the host. There, it digests and absorbs the surrounding tissue. When mature, it leaves the host insect to start the process again. Emergence from the host occurs only when the host is near water. Occasionally, they are found after a cricket or cockroach is killed by someone crushing the insect, at which time the worm begins to wiggle out of the insect's body.

Horsehair worms have also been seen in the caves of Carlsbad Caverns National Park and in streams in the Guadalupe Mountains. They are fascinating, but rarely encountered.

We can guess—fairly accurately—that the park provides habitat for numerous other strange invertebrate animals that are yet to be studied.

Reptiles

Among the 46 species of reptiles in the park are the gray-banded kingsnake, an endangered species in New Mexico, and two state-threatened species: the Rio Grande cooter (a turtle) and the mottled rock rattlesnake. Though rare in the state, the mottled rock rattlesnake is the most common snake seen in the park.

Rattlesnakes are far less common in the park than lizards. Most often seen are the several species of whiptail lizards, spiny lizards, and horned lizards. There are also two species of skinks and one gecko. Among the non-venomous snakes are such diverse animals as the Chihuahuan hook-nosed snake, Trans-Pecos ratsnake, and mountain patch-nosed snake.

The park also provides habitat for four species of turtles, one of which—the ornate box turtle—is not aquatic.

PLANTS

The vegetation communities of Carlsbad Caverns National Park are diverse and, in several cases, unique. This diversity is further benefited by the position of the park at the intersection of the northern Chihuahuan Desert, southern Rocky Mountain, and southwestern Great Plains biogeographic provinces.

The park's diverse ecosystem provides habitat for many plants that are at the geographic limits of their ranges. For example, the ponderosa pine reaches its extreme eastern limit here and chinkapin oak is at the western edge of its range.

There is more diversity of cacti in the Chihuahuan Desert than in any other region. Experts believe that this plant family originated here or to the south, and expanded out through the New World. The park's vascular plant list notes 26 species or subspecies of cacti, including two species that are federally listed.

The plant families with the most species in the park are species in the sunflower family, with 153 species, and grasses, with 135 species. There are more than 60 known species of the legume family and more than 30 each from the mustard and poinsettia families. Other groups with numerous representatives include the mint family (25), milkweed family (15), and ferns (13).

Vegetation Map

Ecologists use the concept of "plant associations" to help describe and recognize patterns in the way vegetation occurs in the landscape. The park's vegetation map, completed in 2003, verifies the uniqueness and diversity of its vegetation. It documents 85 different plant associations in the park. These range from desert shrublands and semi-grasslands of the lowland basins and foothills up through montane grasslands, shrublands and woodlands of the highest elevations.

Of those 85 plant associations, 28 are new associations that were not previously described elsewhere.

The vegetation map documents that more than half the park is shrubland, with 17,858 acres of montane shrubland and 9,295 acres of desert shrubland. About a third of the park (14,586 acres) is covered in various grassland associations. Other smaller map units include 1,753 acres of arroyo riparian woodland and shrubland, 1,765 of woodland, and 1,989 of "other", which includes small areas of some very interesting communities, such as scattered herbaceous wetlands, the forested wetland at Rattlesnake Springs, and various cliff/rock/barren/arroyo communities.

The park's vegetation map and report are available at the Natural Heritage New Mexico website: http://nhnm.unm.edu/vlibrary/pubs/index.php5 (http://nhnm.unm.edu/vlibrary/pubs/index.php5) (Search on keyword "Carlsbad Caverns National Park," then click on the vegetation map entry).

Cacti / Desert Succulents

Ask someone to name a desert plant, and he will probably say "cactus." The plants of the cactus family are the most commonly associated with deserts, especially in the Americas. The cactus family is almost entirely a New World family, occurring as natives in Central, South and North America.

Of all the world's deserts, the Chihuahuan Desert maintains the highest diversity of cactus species. Even though the scientists who name cacti (called taxonomists) don't agree on most of the names of these prickly plants, they do agree there are many different types here.

For example, everybody agrees that the Lee pincushion cactus occurs in Carlsbad Caverns National Park and the immediate vicinity and nowhere else. But this tiny plant has had a dozen names over the years, and even now it goes by at least two official scientific names: Escobaria sneedii var. leei and Coryphantha sneedii var. leei. Luckily, the plants don't care what people call them and go about their business in spite of our confusion.

Using the names the park has chosen to follow, its vascular list notes 26 species or subspecies of cacti. They range from the tiny Lee pincushion and button cacti to the large prickly pears and huge clumps of strawberry hedgehogs. Other colorfully named examples include rainbow cactus and Christmas cholla.

Flowering season and flower color vary among the park's cacti. The tiny pincushions usually put out their pink flowers in spring. The yellow flowers of prickly pears appear in May and the stunning reds of the claret cup cacti show up in June. The purples of strawberry hedgehogs and cane chollas follow.

While cacti do store moisture in their swollen stems and guard it with their spines, they really would not provide a good drink of water if you were thirsty. The moisture is quite thick, sticky, and tastes bad.

Cacti play a key role in providing habitat for wildlife. Their flowers provide pollen for bees, especially those called cactus bees. Their fruits feed rock squirrels, insects, and other wildlife—and people like them too! Their stems (or pads) are popular food for deer and the caterpillars of several species of moths feed inside the pads. Finally, birds, such as the aptly named cactus wren, use cacti as a fortified place to build nests and raise young.

Other desert succulents present in the park include the agaves and yuccas. The New Mexico agave grows at the higher elevations, while the lechuguilla (Agave lechuguilla) is common in the lower elevations. Lechuguilla is considered an indicator plant of the Chihuahuan Desert, meaning that where it occurs is Chihuahuan Desert. The tree-like Torrey yuccas and low-growing banana yuccas grace the lower elevations and provide habitat for yucca moths, which pollinate their flowers as they lay their eggs.

Ferns

Ordinarily, people don't think of ferns when they think of deserts. Of course, most ferns in the world are distributed in wet habitats, especially in warm regions. But our area also has quite a few. They look shriveled and dead much of the time, but that's just one of their adaptations to desert conditions. They use water-saving desert adaptations, such as small fronds (leaves) with shading hairs, scales, or waxy coverings to hold in water. When it rains, the dead-looking dry fronds turn green in a few hours and begin the process of photosynthesis.

The plants referred to as "ferns and fern allies" are plants that have vascular tissue, but do not produce fruits and seeds. They mostly reproduce by spores or vegetative (non-sexual) reproduction. Ferns are very ancient plants that date back more than 300 million years. Their ancestors date back to the Carboniferous period when coal deposits were forming.

Carlsbad Caverns National Park has 13 known species of ferns, including maidenhair fern, cloak fern, lipfern, cliffbrake, and spleenwort. The park's fern allies include one horsetail (also called a scouring rush) and four species of spikemosses, some of which are called "resurrection ferns."

Grasses

According to its vegetation map, about a third of the park (14,586 acres) is covered in grasslands. There are many different grassland plant associations within this group, sometimes with very different species compositions and appearances. Some of the park's grasslands have high shrub cover, as much as 25 percent.

Among the most fascinating of the park's grasslands are those dominated by the grass called curlyleaf muhly (Muhlenbergia setifolia). According to the vegetation map report, these "give the mid-elevation slopes their distinctive character and are part of what sets the landscape of the park apart from most others in the Southwest."

Curlyleaf muhly is a grass that occurs almost entirely in the Chihuahuan Desert, and even here it is rarely very common. The park vegetation map report noted that while similar curlyleaf muhly-dominated communities are found occasionally throughout the range, none are known to dominate their respective landscapes as those in the park do. These associations are among the newly described plant associations for the park.

The grass family is prominently represented on the park's plant list, with 135 known species. Some of them are non-native and a few of those are invasive, damaging species; however, most are native.

Lichens

Lichens are the result of a symbiotic relationship between algae and fungi. At Carlsbad Caverns National Park, lichens can be seen on rocks and tree trunks to a limited extent. More prominent are the black, brown, and white "crusts" that can be seen on the soil surface. These crusts are living organisms, composed of various lichens, algae, mosses, and liverworts. Previously referred to as "cryptogamic crusts," researchers prefer to use more scientifically correct terms, such as "microphytic" (tiny plants) or "microbiotic" (tiny organisms) to describe these organisms.

The crusts don't look very impressive when they're dry, but when it rains they come out of dormancy quickly. Rapidly absorbing moisture, they develop the deeper pigments for photosynthesis. During this time, the plants take advantage of the moisture to grow and reproduce by producing spores.

Microphytic crust can be an important component of arid and semi-arid ecosystems. For example, they prevent soil erosion. This happens two ways. First, the root-like structures of lichens and mosses, along with the filaments of some algae, bind the soil particles together. This often creates an irregular soil surface that interrupts wind patterns, reducing wind erosion and trapping wind-borne soil particles. Second, the crusts physically protect the soil by covering it with their thalli ('bodies'), thereby reducing rain-caused erosion and removal of sediment.

Crusts also improve the moisture content of soils by increasing the depth of water penetration and the total soil moisture content. Crusts may also decrease evaporation from the soil surface, enhancing the higher rain infiltration rates found in crusted soils. Crusts enhance seed germination and seedling development, presumably by providing a stable soil substrate and extra nutrients.

The effects of algae and lichens on soil fertility have been studied extensively. Certain crusts contribute high quantities of nitrogen, an extremely limited nutrient in desert soils. Crusts also contribute organic matter (carbon compounds) to soils.

These crusts tend to be rather fragile and are often severely damaged by mountain bikes, hikers, cattle and fire. Studies have documented varying recovery times, usually measured in decades. These are just some of the plants that benefit when hikers stay on trails.

Marine Plants / Algae

Algae are everywhere. The most famous algae, of course, are the seaweeds and kelps. But you don't need an ocean to have algae. There are many different kinds, some of which exist as single-celled organisms. Some of these microscopic plants live in fresh water. Some live on or in the soil. You've probably seen them in your pets' water dishes, even inside the house. That's because their single-celled reproductive spores are floating around in the air all the time.

In Carlsbad Caverns National Park, most kinds of algae are single-celled. As in many semi-arid and arid desert areas, the algal spore can survive being dried out for long periods of time. Then when water is available they grow into masses that are often visible. When the park gets a good rain, the water percolates down through the various limestone layers until it gets to a less-permeable layer. Then the water travels sideways and eventually runs down the sides of cliffs. You can see this on the Walnut Canyon entrance road. And along with the water running down are populations of algae that appear to stain the rocks black.

Some of these algae live in the caves, too. Under normal light conditions, they will grow on walls or in pools as far into a cave as the sunlight penetrates (the twilight zone). In caves with artificial light sources of suitable wavelengths, such as Carlsbad Cavern, algae will grow in the dark zones near the lights. These algae are considered pest plants, and are kept under control periodically by park staff.

Among the algae that live on the soil is a blue-green alga in the genus Nostoc. This plant, from a very ancient group that was among the first plants on earth, survives the dry periods as spores. After a rain, the algal cells hydrate, begin their biological functions, and begin to photosynthesize. They also make a gelatinous sheath that connects many cells together to form visible ribbons or balls of living algae. After the area dries out again, the Nostoc ribbons and balls dry up and look like black potato chip pieces.

Mosses / Liverworts

The park's mosses and liverworts are part of the living soil crusts, as described under Lichens (link to Lichens section).

Mushrooms / Other Fungi

Dry and sunny as deserts are, they are almost never without fungi. It doesn't seem right, but we mostly hear about the forest mushrooms that grow in lush, moist, dark areas. However, they are essential parts of all ecosystems, including our desert.

First, it's also important to realize that fungi are not plants. They do not have chlorophyll, the pigment needed for photosynthesis. Fungi cannot capture sunlight and manufacture the carbon compounds needed for living.

Second, we should note that mushrooms are really just the above-ground visible structures of many (but not all) types of fungi. They are a mechanism for dispersing the spores with which fungi reproduce and spread. The bulk of fungal activity goes on at a microscopic level, in the hyphae, which are very long structures that are a single cell wide.

One very important type of fungus is ectomycorrhizae (which means external root fungi). These fungi wrap themselves around the tiny root tips and engage in a symbiotic relationship with most plants on earth—scientists say 80 to 95 percent of plants. They take up mineral nutrients from the soil and exchange them with plants for photosynthetically fixed carbon, thereby benefiting the plants and the fungi. Mycoorhizal fungi are therefore very important, constituting a major energy flow pathway in terrestrial ecosystems—including the deserts.

Of course, the park also has mushrooms. They pop up from time to time among the grasses after there has been a good wetting rain.

Trees and Shrubs

Woody plants—trees and shrubs—are the predominant features of much of the park's vegetation. The park's vegetation map documents that more than half the park is shrubland, with 17,858 acres of montane shrubland and 9,295 acres of desert shrubland. Other smaller map units include 1,753 acres of arroyo riparian woodland and shrubland, 1,765 of woodland, and 1,989 of "other," which includes small areas of some very interesting communities, including the forested wetland at Rattlesnake Springs.

Shrubs are prominent on the park's landscape, and even most of the tree species have shrubby growth habits. Few of the park's trees are very tall. The tallest species (ponderosa pine, chinkapin oak, alligator juniper, and bigtooth maple) occur mostly in the western portions of the park on ridgetops and in drainages. These are in the plant groupings called montane woodlands.

In the lower-elevation eastern end of the park, Chihuahuan shrublands prevail. These include several associations anchored by Pinchot Juniper (Juniperus pinchotii), as well as many others centered on such shrubs as sandpaper oak, viscid acacia, ocotillo, mariola, prickly pear cactus, creosotebush, tarbush, littleleaf sumac and mesquite.

The forested riparian wetland area at Rattlesnake Springs (with permanent water) is also home to a tall gallery of native netleaf hackberry trees, cottonwoods and willows. The intermittently flooded riparian shrublands are dominated by Apache plume, mescal bean, green sotol, catclaw acacia, and littleleaf sumac.

The park's vegetation map and report are available at the Natural Heritage New Mexico website: http://nhnm.unm.edu/vlibrary/pubs/index.php5 (http://nhnm.unm.edu/vlibrary/pubs/index.php5). Search on "Carlsbad Caverns National Park," then click on the vegetation map entry.)

The backcountry of Carlsbad Caverns National Park has quite a few delightful surprises for tree lovers. There are the oak-madrone band cove woodlands. Perched in bands along horizontal sedimentary layers, these woodlands contain small clusters of maples, chinkapin, gray oaks and Texas madrones. Canyon bottoms are home to the maple-oak ravine woodlands, with chinkapin oaks and bigtooth maples and sometimes alligator junipers. Chinkapin oaks are trees of the eastern United States that reach the very western limits of their range in southern New Mexico.

Southwestern chokecherry trees, nestled inconspicuously among other trees most of the year, burst into bloom in April, covering their branches with clusters of small white flowers. Their nectar and pollen are extremely popular with insects, and the tasty red fruits are quickly snapped up by all kinds of wildlife.

Shrub life is abundant and diverse in the park. Our native mulberry tree (Morus microphylla) grows only to the height of a good-sized shrub and makes a fruit so popular with wildlife that people rarely see it. Mescal bean produces large clusters of fragrant purple flowers that smell like grape drink. Algerita fills the air with sweet perfume from its small yellow flowers. Lotebush, with the exotic scientific name of Ziziphus obtusifolia, produces a quarter-inch dark blue fruit that reminds some of gumdrops. Mexican buckeye is a beautiful shrubby tree that has pink flowers early in spring and hard, dry fruits that remind us of true buckeyes, to which they are not related. They are related, however, to western soapberry trees, whose fruits produce a soapy substance when they get wet. In the West, many of our cacti get quite large and we consider them shrubs.

Pinchot Juniper

The common shrubby junipers you see in the visitor center area of the park are an ecologically important and unusual species called Pinchot juniper (Juniperus pinchotii). Another of its common names is redberry juniper, but that name is also used for other species of juniper. The scientific name honors Gifford Pinchot, the first chief of the US Forest Service.

It wasn't until 1969 that park staff realized that these junipers weren't the one-seed juniper so common elsewhere in the West (Juniperus monosperma). At that time, park biologist Walter Kittams consulted with botanical experts and determined that the junipers at the park's lower elevations are all Pinchot junipers.

Junipers are dioecious plants, meaning that they have separate trees that produce female reproductive parts (berries or cones) and male reproductive parts (the tiny cones that produce pollen). It's not always easy to tell Pinchot from one-seed juniper if you look at male plants because they look similar. The females produce the seed cones, blue for one-seed junipers and yellow to red and reddish-brown for Pinchot junipers.

This distinction is no small matter ecologically. Most junipers, including one-seed, do not re-sprout from the stump after fire or cutting. But Pinchot juniper vigorously re-sprouts. Therefore, it is naturally adapted to recover from fire.

Among its many attractions for wildlife, Pinchot juniper is a larval host for the juniper hairstreak butterfly (Callophrys gryneus), meaning that the caterpillars eat juniper. The berries of Pinchot juniper are a valuable food source for numerous species of birds (including mockingbirds) and small mammals (ringtail, fox, raccoon). Insects are also known to feed on it.

Pinchot juniper provides valuable cover for numerous wildlife species. Many species of birds use Pinchot juniper for nesting and roosting cover, especially the gray vireo, a bird listed as threatened by the state of New Mexico.

Wildflowers

Carlsbad Caverns National Park has lush vegetative cover when compared to the drier deserts to the west. Woody plants predominate. Unlike Death Valley, for instance, there is almost no bare ground that can suddenly flush with annual wildflowers in an unusual rainy period. While this park's wildflowers are not always as dramatically eye-catching, they are quite beautiful and abundant, with both annuals and perennial plants represented. The huge variety of plants and the mild climate can result in delightful flower surprises in almost any month of the year—especially if you look closely! The tall Torrey yuccas often put up their large white flower clusters in late winter. At the same time, the secretive desert anemones, which spend most of the year hidden underground as tubers, send up delicate flower stalks each topped with one white flower.

If the summer rains materialize (which is not guaranteed), there will be sudden appearances of many interesting flowers, such as the large blue flowers of Lindheimer's morning glory vine and the tiny red flowers of another morning glory called scarlet creeper.

In dry years, the park's perennial plants provide the most reliable flowering. In very dry years, even some of them do not flower or bear fruit.